Atletico Madrid have demanded a compulsory Â£34 million purchase clause from Chelsea as the only condition to allow Saul Niguez join the Champions League winners.
Chelsea want to bring in the Spain International before transfer deadline day and have held talks with Atletico.
Although LaLiga Champions are open to allowing the midfielder go, Chelsea have faced competition from Manchester United.
According to Goal, the Blues are looking to secure an initial loan deal for Saul, but are reluctant to agree to the Spanish sideâ€™s demand to make the move permanent for Â£34m at the end of the season.
Thomas Tuchel side are looking to strike a similar deal to the one they agreed with Real Madrid for Mateo Kovacic in 2018.
Chelsea initially signed Kovacic on loan before deciding to make the transfer permanent for Â£40m the following summer.
Atletico are also refusing to let Saul leave unless a replacement is signed before the deadline.
Atletico Madrid boss, Diego Simeone told the press on Sunday, when asked about Saul, â€œHe knows my view already.
â€œWe talked and I told him what I think and feel. Thereâ€™s not much else.
â€œBetween now and Tuesday, weâ€™ll see. We are open in the knowledge that anything can happen in football.â€